The Comparison of Optical Properties Between Ba0.25Sr0.75TiO3 and Ba0.75Sr0.25TiO3 Thin Films As The Light Sensors Application

An investigation has been carried out to determine the optical properties of Barium Strontium Titanate (BST) thin films, with different chemical composition, namely Ba0.25Sr0.75TiO3 and Ba0.75Sr0.25TiO3. BST thin films that were prepared by the Chemical Solution Deposition (CSD) method and was coated on an Indium Tin Oxide (ITO) substrate using the Spin Coating method at a speed of 3000 rpm for 30 seconds. BST thin films have been characterized using optical microscopy, UV-vis spectrophotometer and X-Ray Diffraction (XRD). The results obtained that the thickness of BST thin films with the composition of Ba0.25Sr0.75TiO3 and Ba0.75Sr0.25TiO3 were 42.7 μm and 28.152 μm respectively, the refractive index value of 2.31 and 2.30 respectively, and they had the gap energy of 3.4 eV and 3.3 eV respectively. From the data obtained data with notes using the same method and treatment, thin film with the chemical structure composition of Ba0.75Sr0.25TiO3 was declared superior for the usageas photodiode sensors.